This application is a national stage of PCT International Application No. PCT/EP2008/007173, filed Sep. 3, 2008, which claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2007 045 960.4, filed Sep. 26, 2007, the entire disclosure of which is herein expressly incorporated by reference.
The present invention relates to a method and apparatus for warning following vehicles in a group of several sequential vehicles, wherein a warning is transmitted from a leading vehicle to a following vehicle.
German patent document DE 10 2004 062 497 A1 discloses a method for reducing the danger of a collision with the rear end of a first vehicle by a following second vehicle. A distance and a relative speed of the following second vehicle to the first vehicle are thereby determined. By means of the distance and the relative speed it is determined if a collision of the second vehicle with the rear end of the first vehicle is imminent, if so, a warning is transmitted from the first vehicle to the following vehicle second vehicle and/or actions are triggered in the first vehicle.
German patent document DE 199 33 782 A1 describes a device for avoiding rear end collisions by the observation of the rear traffic space, where a sensor for measuring the relative speed and the distance between a first and a second vehicle is provided at a first motor vehicle, whose sensor signals are delivered to a computer. The computer controls a device in the first motor vehicle, by means of which a collision-avoiding or collision-reducing action can be carried out.
One object of the present invention is to provide an improved method and apparatus for warning following vehicles in a group of several sequential vehicles.
This and other objects and advantages are achieved by the method and apparatus according to the invention, in which a vehicle (referred to herein as a “middle vehicle”) traveling in a group of sequential vehicles transmits a warning to a “following vehicle” following behind it, if a critical approach of the following vehicle to a “leading vehicle” (traveling ahead of the middle vehicle) is occurring. The critical approach is determined by a control unit of the middle vehicle from a total distance and a total relative speed between the leading vehicle in front of the middle vehicle and the following vehicle, wherein the middle vehicle comprises at least one distance and/or relative speed sensor directed to the front and at least one distance and/or relative speed sensor directed to the rear for determining the relative speed and the relative distance.
By means of the early warning, the following vehicle has a higher reaction time and a longer brake path available, which leads to a reduction of a danger or a severity of a possible collision of the following vehicle with the middle vehicle.
In addition to the occurrence of the critical approach of the following vehicle to the middle vehicle as a criterion for automatically warning the following vehicle, a warning can also be carried out when an imminent front collision of the middle vehicle with the leading vehicle occurs simultaneously with a critical approach of the following vehicle to the middle vehicle. In this manner, a further increase of the reaction time and an extension of the available brake path can be created for the following vehicle, as an earlier warning can be issued.
A rear distance and a rear relative speed between the following vehicle and the middle vehicle are further determined. By means of the front and the rear relative speed, the front and the rear distance and a vehicle length of the middle vehicle, it is possible to determine the total relative speed and the total distance. It is further determined if a collision of the middle vehicle with the leading vehicle is imminent, and if a collision of the rear vehicle with the middle and/or leading vehicle is imminent.
If a front and/or rear end collision of the middle vehicle is imminent, an optical and/or acoustic warning is issued from the middle vehicle to the following vehicle on the one hand. One or several brake lights of the middle vehicle can thereby be switched on automatically as an optical warning and/or switched brighter or in a flashing manner and/or a hazard warning flasher is switched on. A horn of the middle vehicle can for example be actuated automatically as an acoustic warning. An early warning is thereby available to the driver of the following vehicle, by means of which he can initiate an early delay of his vehicle, so as to prevent a possible collision or to diminish its strength.
On the other hand, a measure for the protection of the occupants of the middle vehicle (e.g., a pretensioning of a safety belt, an activation of active headrests or a deployment of a roll-over bar) is triggered with an imminent frontal or rear end collision of the middle vehicle. An early protection of the occupants of the vehicle is achieved thereby, and the occupants are in such a position during a collision that further restraint systems can act optimally on the occupants.
Further, a brake torque of the middle vehicle is increased during an imminent frontal and/or rear end collision during and/or shortly after the collision. By this increase, a maximum delay of the middle vehicle can be achieved quickly, and the severity of the collision with the leading vehicle is reduced or the collision is prevented.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.